#region Apache License
//
// Licensed to the Apache Software Foundation (ASF) under one or more 
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership. 
// The ASF licenses this file to you under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with 
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#endregion

using System;

namespace log4net.Core
{
    /// <summary>
    /// A SecurityContext used by log4net when interacting with protected resources
    /// </summary>
    /// <remarks>
    /// <para>
    /// A SecurityContext used by log4net when interacting with protected resources
    /// for example with operating system services. This can be used to impersonate
    /// a principal that has been granted privileges on the system resources.
    /// </para>
    /// </remarks>
    /// <author>Nicko Cadell</author>
    public abstract class SecurityContext
    {
        /// <summary>
        /// Impersonate this SecurityContext
        /// </summary>
        /// <param name="state">State supplied by the caller</param>
        /// <returns>An <see cref="IDisposable"/> instance that will
        /// revoke the impersonation of this SecurityContext, or <c>null</c></returns>
        /// <remarks>
        /// <para>
        /// Impersonate this security context. Further calls on the current
        /// thread should now be made in the security context provided
        /// by this object. When the <see cref="IDisposable"/> result 
        /// <see cref="IDisposable.Dispose"/> method is called the security
        /// context of the thread should be reverted to the state it was in
        /// before <see cref="Impersonate"/> was called.
        /// </para>
        /// </remarks>
        public abstract IDisposable Impersonate(object state);
    }
}
